Outdoor Soil Research Articles

Mitigating Health Risks Through Environmental Tracking of Pseudomonas aeruginosa.

Pseudomonas aeruginosa is a prevalent nosocomial pathogen and a significant reservoir of antimicrobial resistance genes in residential and built environments. It is also widespread in various indoor and outdoor settings, including sewage, surface waters, soil, recreational waters (both treated and untreated), and industrial effluents. Surveillance efforts for P. aeruginosa are primarily focused on hospitals rather than built environments. However, evidence links multidrug-resistant P. aeruginosa of human origin with activity in built environments and hospital settings. Consequently, tracking this pathogen across all environments is crucial for understanding the mechanisms of reverse transmission from built environments to humans. This review explores public health hygiene by examining the prevalence of P. aeruginosa in various environments, its sequence types, the factors contributing to multidrug resistance, and the identification methods through global surveillance. Whole-genome sequencing with sequence typing and real-time quantitative PCR are widely used to identify and study antimicrobial-resistant strains worldwide. Additionally, advanced techniques such as functional metagenomics, next-generation sequencing, MALDI-TOF, and biosensors are being extensively employed to detect antimicrobial-resistant strains and mitigate the ongoing evolution of bacterial resistance to antibiotics. Our review strongly underscores the importance of environmental monitoring of P. aeruginosa in preventing human infections. Furthermore, strategic planning in built environments is essential for effective epidemiological surveillance of P. aeruginosa and the development of comprehensive risk assessment models.

A comparative study on the optical performance of retro-reflective coatings before and after the aging process

Retro-reflective (RR) materials are largely included among the strategies to mitigate Urban Heat Island (UHI) phenomenon in the urban spaces thanks to their optical directional properties. As materials potentially used in the building exterior envelope, RR materials are subjected to outdoor aging and soiling processes, which could alter their optical behaviour. In this perspective, the investigation focuses on the characterization of the optical performance of several types of RR plaster coatings after outdoor aging and soiling processes. The RR plaster coatings were previously developed and studied, before undergoing the outdoor exposure. The RR samples were developed covering the support with a reflective white paint and glass beads. Five different microsphere diameter ranges and three different microsphere superficial density ranges have been employed. In this paper, the RR plaster coatings were tested in terms of optical properties after outdoor aging and soiling and results were compared with data of the same plaster coatings pre-aging. Generally, all RR aged samples show a lower solar reflectance in the Vis region with respect to the pre-aging conditions. The RR behaviour is qualitatively maintained after aging and soiling. The RR sample made of glass beads of 200–300 μm diameter range could represent the best solution both in pre- and post-conditions and both in terms of solar reflectance and retro-reflective behaviour, regardless of the density of microspheres used.

Methodologies for the collection of parameters to estimate dust/soil ingestion for young children.

Heavy metals, pesticides and a host of contaminants found in dust and soil pose a health risk to young children through ingestion. Dust/soil ingestion rates for young children can be estimated using micro-level activity time series (MLATS) as model inputs. MLATS allow for the generation of frequency and duration of children's contact activities, along with sequential contact patterns. Models using MLATS consider contact types, and transfer dynamics to assign mechanisms of contact and appropriate exposure factors for cumulative estimates of ingestion rates. The objective of this study is to describe field implementation, data needs, advanced field collection, laboratory methodologies, and challenges for integrating into and updating a previously validated physical-stochastic MLATS-based model framework called the Child-Specific Aggregate Cumulative Human Exposure and Dose (CACHED) model. The manuscript focuses on describing the methods implemented in the current study. This current multidisciplinary study (Dust Ingestion childRen sTudy [DIRT]) was implemented across three US regions: Tucson, Arizona; Miami, Florida and Greensboro, North Carolina. Four hundred and fifty participants were recruited between August 2021 to June 2023 to complete a 4-part household survey, of which 100 also participated in a field study. The field study focused on videotaping children's natural play using advanced unattended 360° cameras mounted for participants' tracking and ultimately conversion to MLATS. Additionally, children's hand rinses were collected before and after recording, along with indoor dust and outdoor soil, followed by advanced mass analysis. The gathered data will be used to quantify dust/soil ingestion by region, sociodemographic variables, age groups (from 6 months to 6 years), and other variables for indoor/outdoor settings within an adapted version of the CACHED model framework. New innovative approaches for the estimation of dust/soil ingestion rates can potentially improve modeling and quantification of children's risks to contaminants from dust exposure.

The impact of infrared radiation, solar radiation, and burial exposure on the efficacy of forensic immunoassay testing for blood, semen, and saliva

Determining the biological source of a stain can be important information for both investigators and the judiciary in criminal cases. Immunochromatographic assays are commonly used in forensic science for the identification of human biological material. It has previously been demonstrated that various environmental, thermal and chemical insults can affect the efficacy of ABAcard® HemaTrace® in the detection of human blood. In this study, the efficacy of three tests – ABAcard® HemaTrace®, ABAcard® p30, and RSID™-Saliva – was determined for the detection of blood, semen, and saliva respectively, after the fluids had been exposed to adverse environmental conditions. Each biological fluid was deposited on cotton swatches and exposed to infrared (IR) light using a 100 W heat lamp emitting IR light between 620 and 750 nm and heat of 32° for 24, 36 and 48 h. Cotton swatches bearing biological fluids were also buried in outdoor soil for 3, 4 and 5 weeks. To test common forensic scenarios where biological material may be exposed to solar light, samples were placed on a car bonnet and left for 24, 36 and 48 h. ABAcard® HemaTrace® was able to detect haemoglobin in blood that had been exposed to IR and solar light up to 48 h. False negative ABAcard® HemaTrace® results were obtained from 60 % of blood samples buried for 3 and 4 weeks, and 80 % of blood samples buried for 5 weeks. ABAcard® p30 was able to detect p30 in semen that had been exposed to IR and solar light up to 48 h, except for one false negative after 48 h of IR exposure. False negative ABAcard® p30 results were obtained from all semen samples buried for 3, 4 and 5 weeks. RSID™-Saliva was able to detect α-amylase in saliva in all instances, with no false negative results observed. The findings from this study highlight the need to consider the context in which human blood, semen and saliva are found when reporting on negative immunoassay results.

Indoor-outdoor microbial exchange: Quantifying the contribution of outdoor sources to indoor microbiota across seasons

BackgroundBacteria and fungi are ubiquitous, suspended in the air, and have the potential to influence human health. However, the relationship between microbes in outdoor air, soil, and indoor air remains unknown. MethodsThis study comprehensively analyzed the microbes of indoor air, outdoor air and soil during summer and winter in Nanjing, a hot summer and cold winter city in China. A total of 102 rooms, 544 culturable samples, and 406 sequencing samples were investigated. The Sloan neutral model (SNM) and the fast expectation-maximization microbial source tracking (FEAST) were used to analyze the relationship between indoor and outdoor microbial communities. ResultsThe impact of season on bacterial diversity differed from that on fungal diversity. Microbial diversities and community structures in indoor air, outdoor air, and soil were similar within the same season but differed between seasons. The fitting results of the SNM indicated that the stochastic assembly processes of both indoor and outdoor airborne bacteria were greater in summer than in winter, whereas for airborne fungi, the situation was reversed. The FEAST calculating results suggested that outdoor air serves as a more significant source than soil for indoor air microbiota both in summer and winter. ConclusionThis study provided a new insight into understanding the quantitative contributions of outdoor sources to indoor airborne microbiota. Future studies should include a wider range of building types and extend across multiple seasons to provide deeper insights into the quantitative relationship between indoor and outdoor microbiota.

Estimating postmortem interval based on oral microbial community succession in rat cadavers

The accurate estimation of the postmortem interval has been one of the crucial issues to be solved in forensic research, and it is influenced by various factors in the process of decay. With the development of high-throughput sequencing technology, forensic microbiology has become the major hot topic in forensic science, which provides new research options for postmortem interval estimation. The oral microbial community is one of the most diverse of microbiomes, ranking as the second most abundant microbiota following the gastrointestinal tract. It is remarkable that oral microorganisms have a significant function in the decay process of cadavers. Therefore, we collected outdoor soil to simulate the death environment and focused on the relationship between oral microbial community succession and PMI in rats above the soil. In addition, linear regression models and random forest regression models were developed for the relationship between the relative abundance of oral microbes and PMI. We also identified a number of microorganisms that may be important to estimate PMI, including: Ignatzschineria, Morganella, Proteus, Lysinibacillus, Pseudomonas, Globicatella, Corynebacterium, Streptococcus, Rothia, Aerococcus, Staphylococcus, and so on.

The Impact of Adding Dioxane Derivatives to Polyurethane Structures on their Performance and Degradation in the Environment

The novel dioxane-polyether polyurethanes underwent a 12-month outdoor soil burial test to look into how they would degrade in a natural setting. The structure, thermal properties, surface features, and mechanical strength of the polyurethane films were compared. The initial chemical structure and subsequent chemical alterations were identified using FTIR spectroscopy. The polyurethane samples were less thermally stable throughout the duration of the soil burial test, according to TG/DTG curves. According to all findings, polyurethanes containing 1,3-dioxane-5,5-dimethanol exhibit excellent physical characteristics and mild degradation levels after being buried in soil for a year. These polyether urethanes can break down if the rigid domain structure is exposed to moisture and if microorganisms can spread into the polymer matrix. The physical properties, surface features, and degradation of polyether polyurethanes can be improved by varying the molar ratios of the hard segment components and the dioxane derivative structures.

Organochlorine pesticide contamination of soils and dust from an urban environment in the Niger Delta of Nigeria

The concentrations, sources, and risk of twenty organochlorine pesticides (OCPs) in soils and dusts from a typical urban setting in the Niger Delta of Nigeria were examined. The Σ20 OCP concentrations (ng g−1) varied from 4.49 to 150 with an average value of 32.6 for soil, 4.67 to 21.5 with an average of 11.7 for indoor dust, and 1.6 to 96.7 with an average value of 23.5 for outdoor dust. The Σ20 OCP concentrations in these media were in the order: soil > outdoor dust > indoor dust, which was in contrast with the order of the detection frequency, i.e., indoor dust (95 to 100 %) > soil (60 to 90 %) > outdoor dust (30 to 80 %). The concentrations of the different OCP classes in these media followed the order: aldrin + dieldrin + endrin and its isomers (Drins) > chlordanes > dichlorodiphenyltrichloroethane (DDTs) > hexachlorocyclohexane (HCHs) > endosulfans for outdoor dust and soil, while that of the indoor dust followed the order: Drins > chlordanes > endosulfans > DDTs > HCHs. The cancer risk values for human exposure to OCPs in these sites exceeded 10−6 which indicates possible carcinogenic risks. The sources of OCPs in these media reflected both past use and recent inputs.

The macroecology of butyrate-producing bacteria via metagenomic assessment of butyrate production capacity.

Butyrate-producing bacteria are found in many outdoor ecosystems and host organisms, including humans, and are vital to ecosystem functionality and human health. These bacteria ferment organic matter, producing the short-chain fatty acid butyrate. However, the macroecological influences on their biogeographical distribution remain poorly resolved. Here we aimed to characterise their global distribution together with key explanatory climatic, geographical and physicochemical variables. We developed new normalised butyrate production capacity (BPC) indices derived from global metagenomic (n = 13,078) and Australia-wide soil 16S rRNA (n = 1331) data, using Geographic Information System (GIS) and modelling techniques to detail their ecological and biogeographical associations. The highest median BPC scores were found in anoxic and fermentative environments, including the human (BPC = 2.99) and non-human animal gut (BPC = 2.91), and in some plant-soil systems (BPC = 2.33). Within plant-soil systems, roots (BPC = 2.50) and rhizospheres (BPC = 2.34) had the highest median BPC scores. Among soil samples, geographical and climatic variables had the strongest overall effects on BPC scores (variable importance score range = 0.30-0.03), with human population density also making a notable contribution (variable importance score = 0.20). Higher BPC scores were in soils from seasonally productive sandy rangelands, temperate rural residential areas and sites with moderate-to-high soil iron concentrations. Abundances of butyrate-producing bacteria in outdoor soils followed complex ecological patterns influenced by geography, climate, soil chemistry and hydrological fluctuations. These new macroecological insights further our understanding of the ecological patterns of outdoor butyrate-producing bacteria, with implications for emerging microbially focused ecological and human health policies.

Risks posed by invasive species to the provision of ecosystem services in Europe

Invasive species significantly impact biodiversity and ecosystem services, yet understanding these effects at large spatial scales remains a challenge. Our study addresses this gap by assessing the current and potential future risks posed by 94 invasive species to seven key ecosystem services in Europe. We demonstrate widespread potential impacts, particularly on outdoor recreation, habitat maintenance, crop provisioning, and soil and nitrogen retention. Exposure to invasive species was higher in areas with lower provision of ecosystem services, particularly for regulating and cultural services. Exposure was also high in areas where ecosystem contributions to crop provision and nitrogen retention were at their highest. Notably, regions vital for ecosystem services currently have low invasion suitability, but face an average 77% increase in potential invasion area. Here we show that, while high-value ecosystem service areas at the highest risk represent a small fraction of Europe (0-13%), they are disproportionally important for service conservation. Our study underscores the importance of monitoring and protecting these hotspots to align management strategies with international biodiversity targets, considering both invasion vulnerability and ecosystem service sustainability.

Insights into cork weathering regarding colour, chemical and cellular changes in view of outdoor applications.

A comprehensive analysis of outdoor weathering and soil burial of cork during 1-year experiments was carried out with measurements of CIELAB color parameters, cellular observations by scanning electron microscopy, and surface chemical features analysed by ATR-FTIR and wet chemical analysis. Cork applied in outdoor conditions above and below ground retained its physical structure and integrity without signs of deterioration or fracturing. The cellular structure was maintained with some small changes at the one-cell layer at the surface, featuring cellular expansion and minute cell wall fractures. Surface color and chemistry showed distinct results for outdoor exposure and soil burial. The weathered cork surfaces acquired a lighter color while the soil buried cork surfaces became darker. With outdoor weathering, the cork polar solubles increased (13.0% vs. 7.6% o.d. mass) while a substantial decrease of lignin occurred (about 28% of the original lignin was removed) leading to a suberin-enriched cork surface. The chemical impact on lignin is therefore responsible for the surface change towards lighter colors. Soil-burial induced hydrolysis of ester bonds of suberin and xylan, and the lignin-enriched cork surface displayed a dark brown color. FTIR and wet chemical results were consistent. Overall cork showed a considerable structural and physical stability that allows its application in outdoor conditions, namely for building façades or other surfacing applications. Architects and designers should take into account the color dynamics of the cork surfaces.

Phenylmethylsiloxanes in indoor dust from residential area of China: Source, occurrence, bioavailability and exposure assessment

Phenylmethylsiloxanes, as modified products of dimethylsiloxanes, have been used in personal care products (PCPs) and household appliances, with indoor dust serving as one potential reservoir due to their particle-binding properties. This study measured six isomers of two phenylmethylsiloxanes (P3 and P4) in PCPs (<LOD-381 μg/g, df = 38–43 %, n = 58), indoor dust (<LOD-158 ng/g, df = 33–65 %, n = 103), and outdoor soil samples (<LOD-3.2 ng/g, df = 0–25 %, n = 20) from Chinese Cities. Overall, mean dust concentrations of ∑(P3 + P4) were highest in barbershops (176 ng/g), followed by bathrooms (49.5 ng/g), living rooms (13.3 ng/g), and bedrooms (5.4 ng/g) of residences. Dust phenylmethylsiloxanes had positive correlations with the number of PCPs in bathrooms (R = 0.95 for ∑P3, 0.82 for ∑P4) and electronic appliances (R = 0.86 for ∑P3, 0.84 for ∑P4) in living rooms, suggesting their important contribution to phenylmethylsiloxane emission. The mean concentration ratio of ∑(P3 + P4) to their major degradation product, i.e., PhMeSi(OH)2, in dust was 2.4 times higher than that in soil, indicating stronger persistence of phenylmethylsiloxanes in indoor environment. Simulated experiments indicated bioavailabilities (1.1–8.2 %) of phenylmethylsiloxanes during dust ingestion lower than that (20.4 %) of their degradation product. Dermal absorption of PCPs dominated (>99 %) intakes of phenylmethylsiloxanes for adults, while dust ingestion/adsorption (0.19 ng/d) may play important roles for toddlers/infants with little usage of phenylmethylsiloxanes-containing PCPs. Additionally, total daily intakes of PhMeSi(OH)2 (0.30–0.84 ng/d) via ingestion and dermal absorption of dust were higher than P3 (0.06–0.31 ng/d) and P4 (0.02–0.09 ng/d), suggesting exposure risk of degradation product of phenylmethylsiloxanes deserving attention.

Fate of dimethylsilanediol (DMSD) in outdoor bare surface soil and its relation to soil water loss

Dimethylsilanediol (DMSD) is a primary degradation product of silicone materials in the environment. Due to its low air/water partition coefficient and low soil/water distribution coefficient, this compound is not expected to undergo sorption and volatilization in wet soil. In an accompanying paper, we confirm that under controlled indoor conditions in test tubes, there is little to no volatilization of DMSD from soil and soil constituents if soil is wet. However, a significant amount of DMSD was volatilized when the soil substrates became air dried. Given the importance of water on the partition and fate of DMSD, we now report a continuation of this study focusing on the relation between DMSD removal and water loss in re-constituted soil columns under outdoor conditions. Consistent with predictions based on its partition properties and reconciling this evidence with previously reported field and laboratory studies, DMSD distribution was found to be largely dependent on water partitioning. The results suggested that DMSD moved upward in soil profile as soil water was evaporated from topmost layers with little DMSD retention by the soil matrix. As soil dried, a fraction of DMSD was sorbed by the soil matrix in the topmost layer, while most of the spiked radio-labeled DMSD was removed from soil through volatilization.

Retro-reflective plaster coatings after outdoor aging and soiling: an in-lab optical performance characterization

The potential benefits of highly reflective and retro-reflective (RR) materials on urban context have been performed by several studies through their optical characterization. During their lifetime, outdoor aging and soiling can affect the RR optical behaviour. To this aim, this study investigates the performance of RR plaster coatings after outdoor aging and soiling from May to October 2022 in Perugia, Italy. The same RR plaster coatings in pristine conditions were already characterized in lab in terms of optical performance. In particular, RR samples obtained by using glass beads with different diameters (i.e., 40 ÷ 70 μm and 70 ÷ 110 μm) distributed in three superficial density ranges (i.e., 0.30 ÷ 0.40 kg/m2, 0.20 ÷ 0.30 kg/m2 and 0.10 ÷ 0.20 kg/m2) have been investigated in this study through spectrophotometric and angular reflectivity analyses. In all cases, the post-aging RR samples exhibit lower global reflectance values with respect to the same RR samples in pristine condition. Concerning the angular reflection distribution analysis, a stronger relative RR component was found for the post-aging RR sample with an average diameter of 70 ÷ 110 µm and superficial density distribution equal to 0.10 ÷ 0.20 kg/m2 for each investigated incident direction.

Epidemiology, Mechanisms and Prevention in the Etiology of Environmental Factor-Induced Cardiovascular Diseases.

Cardiovascular diseases are a significant cause of mortality worldwide, and their prevalence can be amplified by a range of environmental factors. This review article critically evaluated the published information on the epidemiology and pathophysiological mechanisms of various environmental factors such as air indoor and outdoor air pollution, water pollution, climate change, and soil pollution. Preventative measures to mitigate these effects including public health responses are discussed with gaps in our knowledge for future studies.

Terra-22: an aerial soil sampling in densely compacted agricultural fields

Soil sampling is used in agriculture to monitor fields and plan fertilizer application. This task is typically performed manually, but ground robots have recently been introduced. However, ground robots are often slow and heavy, which contributes to soil compaction. Fast-flying drones could provide an interesting alternative to ground robots. However, drones are severely limited in their payload and in the forces that they can apply to the soil. This paper presents the Terra-22, the first airborne system capable of sampling densely compacted agricultural soils. To do so, many challenges were addressed, including the development of (i) a high-power density drilling system that outperforms typical brushed DC gear motor by 39%, (ii) a drill design that is 48% lighter than traditional steel auger drills and that keeps cross-contamination under 4%, and (iii) a drill penetration rate controller that reduces the torque requirement by 33% and the axial force requirement by eight folds when compared to a constant penetration speed controller. Outdoor soil sampling tests in a corn field (sandy loam soil, compaction between 0.8 and 2 MPa) demonstrated a 94% success rate on flat terrain and a sampling duration under one minute.

Accelerated weathering of silicate rock dusts predicts the slow-release liming in soils depending on rock mineralogy, soil acidity, and test methodology

The ongoing acidification of soil poses a significant threat to the proper functioning of various ecosystems worldwide. Silicate rock dusts (RD) are increasingly amended to acid soils to restore their pH, but the acid neutralising capacity (ANC) and dissolution rate of these products are highly variable and lack proper assessment protocols. It is expected that pH-dependent RD ANCs and dissolution rates dictate the pH increase in soils depending on the initial pH and pH buffer power of the soil. This study addressed these questions by comparing and validating three accelerated weathering tests for their capacity to predict the gradual liming effects in a two-year outdoor mesocosm. Five commercial RDs (two basalts, phonolite, foidite, and trachy-andesite) were tested in four acidified forest soils varying in initial pH, in texture and associated pH buffer power. First, RD dissolution was measured in aqueous batch renewal systems during one year at various starting pH (3.5, 4.5, and 5.5) and constant temperatures (20 °C, 37 °C, and 65 °C). These showed that the ANCs of RDs exhibit a fast fraction (half-life < 1 day) followed by a slower fraction. Second, titration tests of RDs at fixed solution pH, i.e., pHstat, performed between pH 3.5 and 4.5 revealed surface normalised dissolution rates that decreased factors 10–100 per unit pH increase, the slope depending on the RD’s mineralogy. Indeed, the rate ranking of observed surface area normalised dissolution rates confirmed that of literature-based values, weighed by the XRD-derived mineralogical fractions. Third, lime-calibrated agitated soil-RD suspension tests were conducted for two months, illustrating the dependency of RD ANC on soil context, and yielding ANCs that were factor 2–5 times larger than in the batch renewal test because of pH buffering effects of soil particulates. Finally, an outdoor soil mesocosm on the four acid soils amended with RDs at 12 Mg/ha and 340 Mg/ha was established and soil pH was monitored for 2 years. The observed pH trends corresponded well for both the low dose (R2a = 0.67) and the high dose (R2a = 0.93) with model predictions made using the pH- and temperature-dependent RD dissolution rates (pHstat test) and the soil pH buffer power and RD slow ANC-fraction (soil-RD suspension test). This model predicts half-lives of RD dissolution ranging between <1 month to >100 years depending on the starting pH of the soil, its pH buffer power, the RD mineralogy (XRD based) and its specific surface area. This study shows that the dissolution and ANC of RD can be most pragmatically predicted with a series of lime-calibrated soil-RD suspension tests of maximally two months.

Assessment of legacy and alternative halogenated organic pollutants in outdoor dust and soil from e-waste sites in Nigeria: Concentrations, patterns, and implications for human exposure

E-waste is often processed informally, particularly in developing countries, resulting in the release of harmful chemicals into the environment. This study investigated the co-occurrence of selected persistent organic pollutants (POPs), including legacy and alternative halogenated flame retardants (10 polybrominated diphenyl ethers (PBDEs), decabromodiphenyl ethane (DBDPE), syn and anti-dechlorane plus (DP)), 32 polychlorinated biphenyls (PCBs) and 12 organochlorine pesticides (OCPs), in 20 outdoor dust and 49 soil samples from 7 e-waste sites in Nigeria. This study provides the first report on alternative flame retardants (DBDPE and DP) in Nigeria. The total concentration range of the selected classes of compounds was in the order: ∑10PBDEs (44–12300 ng/g) > DBDPE (4.9–3032 ng/g) > ∑2DP (0.7–278 ng/g) > ∑32PCBs (4.9–148 ng/g) > ∑12OCPs (1.9–25 ng/g) for dust, and DBDPE (4.9–9647 ng/g) > ∑10PBDEs (90.3–7548 ng/g) > ∑32PCBs (6.1–5025 ng/g) > ∑12OCPs (1.9–250 ng/g) > ∑2DP (2.1–142 ng/g) for soil. PBDEs were the major contributors to POP pollution at e-waste dismantling sites, while PCBs were the most significant contributors at e-waste dumpsites. DBDPE was found to be significantly associated with pollution at both e-waste dismantling and dumpsites. Estimated daily intake (EDI) via dust and soil ingestion and dermal adsorption routes ranged from 1.3 to 2.8 ng/kg bw/day and 0.2–2.9 ng/kg bw/day, respectively. In the worst-case scenario, EDI ranged from 2.9 to 10 ng/kg bw/day and 0.8–5.8 ng/kg bw/day for dust and soil, respectively. The obtained intake levels posed no non-carcinogenic risk, but could increase the incidence of cancer at some of the studied e-waste sites, with values exceeding the USEPA cancer risk lower limit (1.0 × 10−6). Overall, our results suggest that e-waste sites act as emission point sources of POPs.

The phytochemical study of Eleutherococcus senticosus (Rupr. &amp; Maxim) leaves in hydroponics and soil culture

Background: In the medical fieldEleutherococcus senticosus (Rupr. &amp; Maxim) (E. senticosus) or Siberian ginseng is known as a natural adaptogen and immunomodulator. All parts of E. senticosus: roots, stems, leaves, and berries, have medicinal properties. In medicine, E. senticosus is used to treat depression, Alzheimer's and Parkinson’s diseases, cardiovascular diseases, cerebral ischemia, and diabetes. The adaptogenic properties of the plant are related to its rich composition of biologically active compounds (phenylpropanoids, eleuterosides, flavonoids, phenolic acids, anthocyanins, vitamins, etc.). E. senticosus activates the body’s protection mechanisms, directly affecting tissue metabolism. It increases mental and physical performance, immunity, and protects from stress, making its use important in sports medicine and the military. The use of E. senticosus in food and dietary supplements has become popular in recent years, whereas some studies suggest that its potential benefits are the reduction of stress and enhancement of immune system function. Objective: To study the content of the main biologically active compounds of medicinal raw material (leaves) of E. senticosus, cultivated in outdoor hydroponics and soil conditions during different stages of growth and development. Methods: The spectrophotometric method was used to determine the content of total phenols, flavonoids, phenolic acids and eleutherosides in a 70 % water-alcohol extract from E. senticosus dry leaves at different phases of vegetation period. The spectra were recorded using an Agilent Cary 60 UV-Vis spectrophotometer. Moreover, the content of extractive substances was determined, and the content of vitamin C, and β-carotene in fresh leaves (State Pharmacopoeia 2015).Results:The results of our study showed that levels of phenolic compounds in the leaves of E. senticosus obtained in hydroponics and soil culture are the highest during the flowering phase (August-September). It was observed that during the flowering period, the content of total phenols, phenolic acids, and eleutherosides was 1.3 times higher, and flavonoids - 1.2 times higher compared to the vegetative phase. It is worth noting that the content of vitamin “C”, β-carotene and extractives was also higher during the flowering period. Hydroponic plants had higher content of vitamin “C”, β-carotene, and extractives, respectively by 1.4, 1.2 and 1.2 times compared to soil plants. This could be due to several factors such as the optimal content of nutrients (N=200 mg/L, P=65 mg/L, K=350 mg/L), and the high content of oxygen in the hydroponic system. Conclusion: According to the results of a phytochemical study of E. senticosus leaves grown in outdoor hydroponics and soil culture in the Ararat Valley, the highest content of biologically active compounds (eleutherosides, phenols, phenolic acids, vitamins) is recorded in hydroponic plants in the flowering period. In general, the research has practical importance,since the E. senticosus plants grown in hydroponic conditions can be a rich source for the production of natural food and dietary supplements. Keywords:biologically active compounds, adaptogen, eleutherosides, flavonoids, phenolic acids, medicinal raw material

Nutritional Value of Soybean under Outdoor Hydroponics and Soil Conditions of the Ararat Valley

Background: Population growth increases the demand for food all over the world. According to the Food and Agriculture Organization of the United Nations, by 2050 the world population will reach 9.1 billion people, for whom food production is expected to increase by 25-70 %. That will lead to an increase in the demand for alternative farming technologies allowing us to ensure higher yields in less time. One such alternative and highly profitable plant growing technology is soilless culture or hydroponics. Climate change, improved technological capabilities, and need to increase self-sufficiency are good reasons for the introduction of soybean in Armenia.Soy, as one of the richest and cheapest sources of protein, plays an important role in the diet of people in many countries. The seed of soybeans contains 17 % oil and about 50 % protein. Because soybeans contain no starch, they are a good source of protein for diabetics.Objective: To establish the possibility and efficiency of soybean cultivation in Ararat Valley by traditional agricultural method and by the regulated hydroponic system and to investigate the nutritional value of soybean seeds.Results: The cultivation method had some influence on soybean yield and on the biosynthesis of several nutritional components. Thus, soilless culture conditions contributed to the increase in soybean yield: the weight of seeds obtained from one plant was 38.7 g while in the soil it was only 19.9 g. Soil plants were distinguished by the maximum accumulation of fat (28.9 %), while hydroponic ones by the maximum content of protein (31.5 %) and sugar (6.3 %).Conclusion: The obtained results established the effectiveness of soybean cultivation in Armenia. The regulated hydroponic method ensures obtaining about 11.6 tons ha-1 of soybean seeds, 3.7 tons ha-1 of protein and 2.6 tons ha-1 of fat. The work was supported by the Science Committee of the Republic of Armenia, in the frames of the research project N 21T-4B167.Keywords: Glycine max (L.) Merr., soilless culture, proteins, fats, sugars